Republic of the Philippines
POLYTECHNIC UNIVERSITY OF THE PHILIPPINES
OFFICE OF THE VICE PRESIDENT FOR ACADEMIC AFFAIRS
COLLEGE OF ENGINEERING
ELECTRONICS ENGINEERING (ECE) DEPARTMENT
ACCOMPLISHMENT REPORT
TO:
Prof: Ma. Elena A. Noriega
FROM:
Group 4
PROJECT:
Experiment
No.:
DATE:
MEMBERS
LEADER:
Mariano, Liera
BS ECE 2-5
4
Title:
Bipolar Junction Transistor
Amplifiers
July 18, 2023
TASKED ACCOMPLISHED
Simulates, solves, and
recorded the result of the
experiment.
Grencio, Mark
Build the circuit using
Angelo
breadboard, simulates and
solve the computation for the
input voltages.
Locsing, Nebrylle
Stated the objectives and
Andre
discussion of the experiment.
Malabayabas, Renz Draw and sketch the result of
the experiment appeared on
the oscilloscope.
Manila, Reniel Josh
Prepared the procedure
needed for the laboratory
experiment.
Marmol, Maureen
Documents the experiment
and provided the observation
for the report paper.
Pacris, Joyce Ann
Accomplished the report
paper and affirmed the
conclusion of the
experiment.
Problems Encountered: None
Remedies: None
REMARKS
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
SIGNATURE
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POLYTECHNIC UNIVERSITY OF THE PHILIPPINES
OFFICE OF THE VICE PRESIDENT FOR ACADEMIC AFFAIRS
COLLEGE OF ENGINEERING
ELECTRONICS ENGINEERING (ECE) DEPARTMENT
DATA
After completing the experiment, the group collected the following data
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GATHERED VALUES
Voltage Gain
Measured
Values
8V
Voltage Gain
Computed
Values
1.41 V
9.4 V
8.8 V
1.69 V
1.62 V
8 V / 100 Hz
12.2 V
10.4 V
1.99 V
1.96 V
10 V / 300 Hz
14 V
15 V
2.1 V
1.98 V
Input Signal
Voltage Output
(Transistor 1)
Voltage Output
(Transistor 2)
5 V / 50 Hz
4.4 V
7 V / 70 Hz
1.39 V
Actual Experiment Documentations
PROBLEMS ENCOUNTERED
It is confusing for us to determine where
we are going to place the cord of the
oscilloscope and function generator in the
circuit.
REMEDIES
We search different instructions in
internet that is related in testing BJT and
conduct a trial and error in our
experiment.
Republic of the Philippines
POLYTECHNIC UNIVERSITY OF THE PHILIPPINES
OFFICE OF THE VICE PRESIDENT FOR ACADEMIC AFFAIRS
COLLEGE OF ENGINEERING
ELECTRONICS ENGINEERING (ECE) DEPARTMENT
FINAL REPORT
EXPERIMENT NO.
EXPERIMENT TITLE:
I.
4
Bipolar Junction Transistor Amplifiers
OBJECTIVES
1. To build a transistor amplifier circuits Common Emitter, Common Base
and Common Collector.
2. To quantify voltage and current in input and output terminal.
3. To contrast the value that was gained in the actual circuit and with the
computed values.
II.
DISCUSSION
Common Emitter, Common Base, and Common Collector are the three
bipolar junction transistor amplifier designs. Their properties and circuit
connections vary. In a common emitter amplifier configuration, the transistor's
base terminal is wired up to the input signal. The collector has the output. It is
referred to as a common emitter amplifier because the grounded terminal serves
as the emitter. Both current gain and voltage gain are present in this amplifier
design. Another amplifier is a Common Base Amplifier Configuration, in which the
output signal is measured at the transistor's collector while the input signal is
connected to the emitter terminal. The grounded terminal is the Base. The input
signal for an amplifier is placed at the transistor's base, and the output is located
at the emitter terminal. The collector is the grounded terminal. The circuit has a
current gain but no voltage gain when using a common collector. It should be
remembered that the transistor's input terminal must be forward biased and its
output must be reverse biased in order for the transistor to function as an amplifier.
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OFFICE OF THE VICE PRESIDENT FOR ACADEMIC AFFAIRS
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III.
BLOCK DIAGRAM/SCHEMATIC
IV.
MATERIALS
o Breadboard, Resistors, Capacitors, and Jumper Wires
o Transistor NPN
o Single Polarity Power Supply
o Oscilloscope
o Function Generator
o Alligator Clips
V.
PROCEDURES
1. Prepare all the components and equipment required in creating a voltage divider,
including: Bipolar Junction Transistor (BJT), breadboard, capacitors, resistors,
jump wires, oscilloscope, power generator, function generator, and voltmeter.
2. Insert the BJT into the breadboard. Make sure to identify the three leads: the
emitter, base, and collector.
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3. Insert the resistors and capacitors into the breadboard and connect them to the
appropriate leads of the transistor. Connect the base resistor between the base
lead of the transistor and the positive power rail on the breadboard. Connect the
collector and emitter resistors as required for your circuit design.
4. Connect the positive terminal of the power supply to the positive power rail on the
breadboard. Connect the negative terminal of the power supply to the negative
power rail on the breadboard. Use jumper wires to make the required
connections between the transistor leads, resistors, capacitors, and the power
supply. Ensure that you make the correct connections based on your circuit
design.
5. Connect the function generator and oscilloscope to the circuit to test the sine
wave of the signal.
6. Measure the Voltage Output in both BJTs and the Voltage Drops across it using
voltmeter. Adjust the power supply voltage and frequency to get different
measurements in the circuit.
7. Provide a manual calculation that will justify the accuracy of the measured data.
VI.
TABLES
Input Signal
Voltage Output
(Transistor 1)
Voltage Output
(Transistor 2)
Voltage Gain
Computed
Values
Voltage Gain
Measured
Values
5 V / 50 Hz
4.4 V
8V
1.41 V
1.39 V
7 V / 70 Hz
9.4 V
8.8 V
1.69 V
1.62 V
8 V / 100 Hz
12.2 V
10.4 V
1.99 V
1.96 V
14 V
15 V
2.1 V
1.98 V
10 V / 300 Hz
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VII.
COMPUTATIONS
Voltage Gain
𝐴𝑣 =
𝑉𝑜𝑢𝑡
𝑉𝑖𝑛
, 𝐴𝑣𝑡 = 𝐴𝑣1 × 𝐴𝑣2
Input Signal: 5𝑉⁄50𝐻𝑧
𝑉𝑖𝑛 = 5𝑉 ; 𝑉𝑜𝑢𝑡1 = 4.4 𝑉 ; 𝑉𝑜𝑢𝑡2 = 8 𝑉
𝐴𝑣1 =
4.4 𝑉
5𝑉
= 0.88 𝑉 ; 𝐴𝑣2 =
8𝑉
5𝑉
= 1.6 𝑉
𝐴𝑣𝑡 = 0.88 𝑉 × 1.6 𝑉 = 𝟏. 𝟒𝟏 𝑽
Input Signal: 7𝑉⁄70𝐻𝑧
𝑉𝑖𝑛 = 7𝑉 ; 𝑉𝑜𝑢𝑡1 = 9.4 𝑉 ; 𝑉𝑜𝑢𝑡2 = 8.8 𝑉
𝐴𝑣1 =
9.4 𝑉
7𝑉
= 1.34 𝑉 ; 𝐴𝑣2 =
8.8 𝑉
7𝑉
= 1.26 𝑉
𝐴𝑣𝑡 = 1.34 𝑉 × 1.26 𝑉 = 𝟏. 𝟔𝟗 𝑽
Input Signal: 8𝑉⁄100𝐻𝑧
𝑉𝑖𝑛 = 8𝑉 ; 𝑉𝑜𝑢𝑡1 = 12.2 𝑉 ; 𝑉𝑜𝑢𝑡2 = 10.4 𝑉
𝐴𝑣1 =
12.2 𝑉
8𝑉
= 1.53 𝑉 ; 𝐴𝑣2 =
10.4 𝑉
8𝑉
= 1.3 𝑉
𝐴𝑣𝑡 = 1.53 𝑉 × 1.3 𝑉 = 𝟏. 𝟗𝟗 𝑽
Input Signal: 10 𝑉⁄300𝐻𝑧
𝑉𝑖𝑛 = 10 𝑉 ; 𝑉𝑜𝑢𝑡1 = 14 𝑉 ; 𝑉𝑜𝑢𝑡2 = 15 𝑉
𝐴𝑣1 =
14 𝑉
10 𝑉
= 1.4 𝑉 ; 𝐴𝑣2 =
15 𝑉
10 𝑉
= 1.5 𝑉
𝐴𝑣𝑡 = 1.4 𝑉 × 1.5 𝑉 = 𝟐. 𝟏 𝑽
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VIII.
GRAPHS/SKETCHES
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IX.
OBSERVATION
For this experiment the group was assigned to do an activity about Bipolar
Junction Transistor (BJT). The base (B), emitter (E), and collector (C) are the three
terminals that make up a BJT. It is a semiconductor device capable of intensifying
or magnifying a signal. It consists of two p-n junctions. The voltage gain represents
the ratio of output voltage to input voltage and current gain reflects the ratio of
output current to input current, these are the two significant amplification variables
for BJTs. While performing the experiment the members also made sure to
observe proper biasing because in order for the BJT to function in its active region
that is truly necessary. Different biasing placements can really affect the
transistor’s qualities and properties.
The group required the use of specific equipment in order to carry out the
experiment quite successfully. This includes a function generator, a power supply,
and a digital oscilloscope provided from the ECE laboratory. The group gained
quite practical and hands-on experience with the equipment, which helped them
to comprehend and understand the purpose and nature of the activity.
By carefully following the prescribed procedures, we successfully generated
sinusoidal waves on the oscilloscope and proceeded to document the
corresponding values. Moreover, we observed an important relationship between
the calibration of both the power supply and the function generator to the behavior
of the displayed sine waves on the oscilloscope.
While performing the activity using the aforementioned materials and
devices, our group made noteworthy observations regarding the output in relation
to the input. Notably, we discovered that as the input signal increases, the output
voltage gain of both transistor 1 and transistor 2 also increases. Furthermore, upon
measuring and calculating the voltage gain of the overall circuit, we were able to
determine the observation about its increasing values. Through analysis, we
established a correlation between the inputs and outputs, contributing to a deeper
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understanding of the circuit's functionality in relation to oscilloscope and function
generator.
X.
CONCLUSION
In conclusion, after the conduct of the experiment, the objectives were
successfully achieved through the construction and analysis of transistor amplifier
circuits, specifically the Common Emitter, Common Base, and Common Collector
configurations.
The group was able to accomplish the first objective by building these
amplifier circuits, allowing them to investigate their individual characteristics and
performance. Likewise, the experiment focused on quantifying the voltage and
current at the input and output terminals of the circuits. By measuring and
recording these values, they were able to gain insights into the behavior and
efficiency of each amplifier configuration. Lastly, the third objective aimed to
compare the experimental results with the computed values. This analysis enabled
the team to evaluate the accuracy of our theoretical calculations and assess any
discrepancies between the predicted and actual outcomes.
In summary, this laboratory experiment provided a comprehensive
understanding of transistor amplifier circuits and their practical applications. By
achieving the stated objectives, we were able to validate the theoretical concepts
and evaluate the performance of the constructed circuits, thereby enhancing our
knowledge of electronic amplification systems.